Blowpipe



J. HARRIS.

BLOWPIPE.

- APPLICATICN FILED MAR. 29. 1918.

Patented Feb. 28, 1922.

UNITED STATES PATENT OFFICE;

101m mars, or'mxnwoon, onto.

BLOWPIIEE.

useful. Improvement in Blowpipes, of whichthe following is a full,clear, and exact description, reference being had to the accompanyingdrawings. r

This invention relates to 'blowpipes such as are employed in the arts ofcutting and welding with gases. It is the general object of my inventionto provide .a blowpipe which is particularly efficient in operation.More limited objects of the invention are to provide a blowpip'e havinga construction and arrangement of passageways whereby, by a merevariation in the cross-sectional areas'of such passageways, the samestyle of pipe may be used for all of the commercial gases and vapors; toprovide a blowpipe which will not only burn all of such gases andvapors, but one wherein the flame will not blow out under suchvariations of pressure as are employed in cutting different thicknessesof metal; also to provide ablowpipe wherein back-firing in the highpressure oxygen passageway will be prevented; to provide a blowpipewherein the preheating operation may be accomplished more quickly andwith a smaller gas consumption than is possible withany other form ofpipe with which I am familiar; to provide a blowpipe the tiporificeswhereof are readilv and conveniently cleaned without the necessity fordisassembling; to provide a blowpipe wherein a supply of cutting oxygen,ample in quantity and uniform in pressure, will be secured at alltin1es,'wit-h no restriction such as exists in the ordinary typeofdrilled or bored-head pipes; to provide for such pipes a new and Vefficient arrangement of the oxygen injector for the preheating jets ororifices; and toprovide a novel construction of'valve for the cuttingoxygen. I secure these results and advantages in and through theembodiment of my invention illustrated in the drawings forming part-hereof,'wherein Fig. 1'represents a side elevation of such blowpipe;Fig. 2 anenlarged central vertical sectional 'view through the blowpipehead and'tip and the adjacent ends of the pipes conveying thevariousgases theretoyXFig. 3' a sectionalv view corresponding to the line 3-3of Fig. 2; Fig. 4 a sectional "viewcorresponding to theline 4-4: of Fig;1; Fig. 5

Specification of Letters Zfatent.

a sectional View corresponding to the line ways in a casting 5 to whichthe rear end ofthe sleeve 1 is, secured, as by means of a screw 6.Projecting from the rear end of w Patented Feb. 28, 1922.. Applicationfiledill a'rch 29, 1918. Serial No. 225,431.

the casting 5 are the connections 7 and 8, i

the former connection receiving oxygen and the latter connection acombustible gas or vapor. The flow of oxygen through appropriatepassageways in the casting 5 (not shown) to the tubes 2 and 3 iscontrolled by a valve 9' while the flow of combustible gas from theconnection 8 and the casting passageway (not shown) to the tube at iscontrolled by'the valve 10. v

The pipe 2 conducts oxygen for cutting purposes to a blowpipe'head andis provided with a valve, which will now be described; This valvecomprises" generally a casing 11 having a rearwardly extendingconnection 12 for oneof the branches of the tube 2 and a forwardlyextending connection 13 for the other branch of said tube. The casing ispreferably formed as a casting having a head provided with a centralbore 14 in which. there is reciprocably mounted a valve-operating stem15, the inner portion of said stem being reduced to provide an annularpassageway therearourfd within said bore. The outer end of the stempasses through a suitable stufiing box'l6 and is adapted. to be engagedby a lever 17 pivoted between a pair of forks 18 (as indicated at 19)extending; forwardly .froin the head. 'Thejrear endj'of the lever'17projects beyond the front end-' bf the handle 1, in convenient positionto be grasped by the operator when it is desiredto open the valvecontrolling the supply of cutting oxygen. The inner end of the bore 14communicates with a cylindrical chamber 20 withinthe casing 11, therebeing an outwardly projectingannular said bore. The valve is mountedwithin the chamber 20 and. comprisesa body 22, prefer abl of brass andhexagonal in shape, said chamber 37 in the blowpipehead and thepast5 -boy having, at one end thereof an annular recess in which" there ispressed a rubber valve 23, thisv valve being held within the recess bypressing inwardly the outer wall surroundingthe same, as indicated at21.

The end of the casing 11 which is'oppositethe lever 17 is provided witha cap 24 threaded thereupon, and between said cap and the valve body 22a helical spring 25 is interposed, said spring normally holding thevalve to its seat.

The rear branch of the oxygen pipe 2 communicates with the chamber 20 bymeans of an inclined passageway 26 while the front or forward branch ofsaid pipe communicates with, the bore 14- by an inclined passageway 27.

At their front'ends, the pipes 2, 3 and 4 are connected to the rearv ofthe blowpipe head 28 and communicate respectively with a chamber 29. andassageways 30 and 31 in said head. The c amber 29 is cored and branched,the front ends of'the branches merging, as shown at 29, above thecentral head passageway 32 for the cutting oxygen. Between the branchesof the chamber as the head is drilled, as indicated at 33 to provide achambered passageway extending nearly in the same direction as thecentral oxygen passageway 32 and forming only a slight angle therewith.The upper portion of the passageway 33 is threaded for the accomodationof the injector by which the preheating oxygen is enabled to inject andform a preheating mixture with the combustible gas supplied through thepipe 4 and passageway 31. The injector is formed as part of the plug 34,the lower end whereof is enlarged and threaded to engage the threadwithin the chambered passageway 33,'as indicated at 34. The lower end ofthe plug is provided with a central bore or passageway 35 communicatingby cross ports 35 with the annular space provided between the reducedportion of the plug and the interior of the chambered passageway 33above said head and with which annular space or chamber the passageway30 communicates. The upper end of the injector plug is provided with ahead 34*, between which and the adjacent surface of the blowpipe thereis inserted a suitable packing washer 34. The lower end of the head 34is tapered, and this tapered end extends across the passageway 31. Withthis arrangement,,preheating oxygen is supplied to the bore 35 throughthe cross bores or passageways 35 and serves to inject the combustiblegas supplied through pipe 4 and passageway 31 and to form an intimatemixture therewith during the flow of such gases through the passageway,36 (forming an axial continuat on of the passageway 33) through theannular sageways provided between the tip members.

The chamber 37 extends upwardly from the lower end of the head 28 andmerges with a reduced internally threaded chamber the upper end'of whichin turn merges with the passageway 32. This internally threaded chamberreceives the u per end of the inner tip member 38 whlch is threadedthereinto, as indicated at 38.

The tip as a whole comprises an' inner member 38 and an outer member, tobe referred to hereinafter. he inner member comprises a plug having acentral axial bore 39 of the same diameter (throughout the major portionof its extent) as and adapted to register with thepassageway 32.

'At 1ts lower end, the bore 39 is reduced to provide a restricteddischar e passagewa 39,, the wall of the bore 39 eing tapere asindicated at 39?, to facilitate the even flow of the gas from the largerto the re stricted portlon of the central bore. The tip plug 38 isprovided with .a cylindrical upper enlargement 40 and below the lower onof such enlargement with a short cylindrical' enlargement 41 mergin atits lower end with a frusto-conical sur ace 42; The portions 40, 41 and42 are adapted to fit snugly within the outer tip member, as will beexplained hereinafter. These projections or enlargements provide meansfor centering the inner tip member within the outer tip member and alsomeans wherebypassageways may be provided for the mixture of preheatinggases conducted to the delivery end of the pipe.

40 denotes slots, preferably V-shaped or triangular in crosssection,which extend radially inwardly from the outer wall of the projection 40and which serve to conduct the mixture of gases within the chamber 37 toa series of V-shaped or triangular slots 41 and 42 extending radiallyinwardly from the outer surfaces of the tip portions 41and 42 andproviding passageways for the preheating gases. Three such slots 4O areshown, and their aggregate cross-sectional area is suchas to conduct thegases freely from the chamber 37 to the slots 41 and 42 The slots 42 areformed as continuations of the slots 41 and, as shown particularly inFig. 8, extend inwardly as nearly as possible to the central bore of theinner tip member, the bottoms of the'slots 41 being parallel with thesaid bore while the bottoms of the slots 42 are inclined towards saidbore at a slightly'less angle than the outer sides thereof. The bottomsof the slots 42 are not exactly, parallel with theoutersurface 41 butare inclined toward such outer l inner cylindrical and frusto-conicalwalls of the outer tip member are adapted to form a close fit with theportions 40, 41 and 412- of the inner member; and the outer a'ndinn'ertip members are usually fastened in operative relation to each other, asby means of a I pin (not shown) A leak-proof joint is provided betweenthe outer tip member. and the bottom of the, head 28 by means of apacking washer 4+ witliin a gland nut 45 which is threaded onto thelower end of said head.

I have found that, by inclining the surface42at .an angle of about4-1/2" to the axis or bore of said inner member and by forming thepassageways 42 in the manner .shown and described, I am enabled toobtain very important, advantages in operation. For instance, I amenabled to impinge the ignited preheating gases more" nearly upon asingle spot of 'metal (in the line of the 3Qaxis of the tip) than 'ispossible with any other form of blowpipe with which I am familiar; thisresults in a ,more nearly instantaneous preheating of the metal with aminimum consumption of gas. The particular shape of the slot-scontributes to this result. Moreover this particular shape of 40weakening th tipso! as to render it incapable of withstanding theincidents of use.

In what is known to the trade as a No. 1

tip, thev diameter of the central bore 39 is the same as that of a No.56 drill.

42 are shown. and the area of the discharge end'of each of said slotsvaries as follows, with the same diameter of'central bore, with the useof different gases i v with acetylene, 25/1000 square inch;

with carbo-hydrogen, 35/1000 square inch; with hydrogen, 41/10 00 squareinch; with artificial gas, 42/1000 square inch with natural gas, 45/1000square inch;

with thermalene, 45/1000 square inch.

These dimensions will insure the productionof a maximum size preheatingflame for the particular size of cutting jet or O I'1fiC B specified. Intips of greater capac1ty,,1t

will be necessary only to preserve the same burn all of the abovementioned gases and Six slots cleaned by means of wires inserted throughthe lowerends thereof.

' So far as I am advised, the tip shown and described herein is the onlystyle of tip. or blowpipe that will burnall of the gases above specifiedand such gases ,as'casing gas, rock gas, gasolene vapor, alcohol vapor,and, generally. all of the commercial gases by a mere variation in thecross-sectional area of the slots 41*, 42*. 'Because ofthe particulartaper, of the lower end of the inner member or plug and the consequenttaper or inclination given to the slots 42, the tip will will do sowithout the blowing out of the flame under the range of pressuresordinarily employed in cutting diiferent thicknesses of metal.

By the particular arrangement of injector (extending as nearly aspracticable in the same direction as the preheati g passageavays and thecentral duct for high pressure oxygen) a maximum efliciency is secured1n the mixing of the preheating gases and in their delivery to theslotted passageways. of the tip.

The manner of forming the chambered oxygen passageway 29 in the headprovides therein a large high pressure. oxygen chamber which secures anample supply of suchoxygen to the central bore. of thetip and an evenpressure within such bore; there is no restriction of the oxygen supplysuch as exists in blowpipes wherein this gas is supplied through adrilled or bored passageway. I100 The high pressure oxygen valvedescribed herein is particularly eflioient in operation. The hexagonalor angular shape of the body 22 enables the oxygen freely to enter thechamber 20; the-rubber valve body 23 can not mar or injure the narrowannular seat 21, The oxygen, being supplied to the chamber 20, assistsnormally in holding the valve body .22 to its seat, enabling me to use alight tension spring 25, which makes it extremely easy! to unseat thevalve by the, operation of the handle of the lever 17. Furthermore,

the valve body 22 is extremely cheap of production and, when therubber=-valve portion thereof becomes worn, it may be convenientlyremoved and replaced with a new one at the place of use and at atrifling expense.

The great majority of all back fires which occi1 r within blowpipes isdue to the leak-- age between the tip and the head into thehigh-pressure connection. As blowpipes are usually constructed, the ductfor high pressure oxygen therein is formed jointly of passageways orbores in the head and in the tip. After the pipe becomes heated throughoperation,"- there is an unequal expansion ofthe metal in the head andthat in the tip, resulting in a separation or breaking of the jointbetween the hea and the tip which allows the preheating gases' and thehigh l,30

pressure oxygen to form an explosive mixture 1n the high pressureoxygenpassageway. I have been able to obviate this leak tering with andforming with the passageproximatel 1/100 high way 32 and bore 39 a ductfor the high pressure oxygen. This washer, by its capability ofexpansion after compression by the upper end of the plug 38, effectuallytakes care of the unequal expansion between the head and the tip afterthe blowpipe becomes heated, malntains a closed joint between the headan'dthe tip, and thus prevents the leakage of preheating gases into thehigh pressure oxygen duct.

To secure the best results the walls of each of the slots 42 form anangle of about with each other. The opposite walls of each web(intermediate adjacent slots) are substantially parallel; and the bottomor inner walls of the slots can be brought into extremely closeproximity to the central bore by this arrangement.

' Having thus described my invention, what I claim 1s:

1 In a blowpipe, the combination of a head, and a tip connected thereto,said tip havmga central bore for cutting oxygen and having a pluralityof V-shaped passage waysfor preheating ases rouped about and convergingtoward the elivery end of said bore at an angle of approximately fourand one-half degrees;

2. Ina blowpipe, the combination of a head, and-a tip connected thereto,said tip having a central bore therethrough and having a plurality ofV-shaped passageways for preheating gases grouped about said bore andconverging toward the'delivery end of said bore at an an le ofapproximately 4-1/2", the upper en s of said passageways being deeperthan the lower ends thereof and the lower ends of said passageways beingapfrom said bore. 3. In a lowpipe the combination, of a head, and a tipdetachably connected thereto,'-said'tip. comprlsing van innermemberhavin a central bore, the lower or discharge end 0 said innermember being-tapered wards said central bore at an angle ofapproximately four and one-half degrees and provided in such taperedportion with inwardly; extending V-sha'ped slots and an 7 outer membersurrounding the inner memher and havingits lower end tapered to conformto the tapered end of the inner mem her and to provide therewith anouter wall for each of,- said slots, the delivery ends of said slotsbeing approximately 1/100 inch from the delivery end of said bore.

4. In a blow ipe,-thecomb1nat1on of a.

head, and a tip etachably connected thereto,

bore at an angle of approximately four and,

one-half degrees, such tapered lower end being provided with V-shapedslots extending inwardly from the outer surface toward said bore, theupper ends of said slots being deeper than the lower end sthereof andthe lower ends of said slots being approximately 1/100 inch from saidbore, and an outer 5. In a blowpipe, the combination, with a thepreheating gases conducted through the first mentioned passageway.

6. In a blowpipe, the combination, with a head having a chamber forpreheating gases and provided with a longitudinally extending passagewaycommunicating therewith, of an injector in said passageway, saidinjector having a central bore at the lower portion thereof for oxygen,there being at passageway for conducting a combustible gas to the firstmentioned passageway adjacent the delivery end of said injector, saidhead having a duct for cutting oxygen, and

:a tip having a centralbore arranged to" receive cutting oxygen fromsaid .ductand provided with passageways for theprehea'ting gasesconducted through the first mentloned passa eway.

7. n a blowpipe, the combination of a head having a branched chamber,for cutting oxygen, and a, tip having a central borefor such cuttingoxygen and passageways for preheating gases surrounding said bore, saidhead having a passageway 'QXtGildlIlg through said chamber andapproxlmately in the' direction of said preheating passage- 'ways andsaid bore and also having passageways f r preheating'oxylgen andcombustible the first mentioned gas communicating wit passageway, and aninjector in said first mentioned passageway arranged to conductpreheating oxygen in operative relation to the delivery end of thepassageway for com bustible gas.

8. A valve for cutting-blowpi es comprising a cylindrical chamber anmeans for conducting fluid thereto, an angular valve body in saidchamber and having at one end thereof a valve of compressible material,an outlet passageway extending from said chamber, an annular valve seatsurrounding said passageway and adapted to engage said valve, an inletpassageway communicating with said chamber, a stem in said outletpassageway for unseating said valve, and a spring in said chambertending to hold the valve on its seat.

9. A valve for blowpipes comprising an angular metal body having anannular recess in one end thereof, and rubber in said recess, the metalwall surrounding said recess being pressed inwardly to retain the rubberwithin said recess.

10., In a blowpipe, the combination of a an angle of substantially 60,and an outer tip member surrounding the delivery portion of the innertip member and closing the outer sides of said slots.

In testimony whereof, I hereunto aiiix my signature.

JOHN HARRIS.

